Protected pile



June 15, 1937. w. B. BLACKMAN A2,083,592 l PROTECTED PILE File NOV. lO, 1934 2 Sh-eelzs-Sheel'I 1 Inl/enfer fazrz Mlackm'an.

v mw? June A15, 1937.

J. W. B. BLACKMAN PROTECTED PILE Filed Nov. l0, 1934 2 sheets-sheet? Patented June 15, 1937 UNITED STATES PATENT OFFICE PROTECTED PILE J chn W. B. Blackman, Long Beach, Calif. Application November 1o, 1934, serial No. 752,445

8 claims.

rIhis invention relates generally to protected concrete or wood piling, and presents various novel features and improvements over past practice, both with respect to structure and methods of casting protected concrete piles.

The necessity has long been realized of rendering concrete piling immune to attack and deterioration by the action of sea water, alkalies, acids, frost, marine insects and the like.

1o One of the most generally used and successful methods employed in the past has been to rst cast the pile of concrete having sufficient porosity to be capable of impregnation to a substantial depth by waterproong material, such '1.5 as asphalt, to then heat the pile to exclude air and other gases from the pores of the concrete, and nally immerse it in a bath of hot asphalt under such conditions that the asphalt is drawn into the pores to impregnate the outer depth of v the concrete. While this method of protecting piles has been found fully successful, it involves a practical disadvantage by reason of the necessity for a fairly large and expensive plant to carry out the impregnating operations. For this and the further reason that a sufficient number of piles is not required on the average job to warrant building an impregnating plant for that job, it has been customary to cast and impregnate the piles at a distant permanent plant, u and then to ship them to the place where they are to be used. It will be apparent, of course, that because of the great size and weight of the average concrete pile, handling and shipping involve considerable expense, particularly where the piles must be transported long distances and to places not conveniently accessible.

One of the outstanding advantages of the invention is that it provides a method whereby protected concrete piles may be cast on the job, at the place where they are to be driven, thus eliminating the difliculties and expense incident to transporting the completed piles. In addition, the invention offers the further advantage of providing protected concrete piling which from structural standpoints, has greater strength and greater immunity from attack by the various agencies mentioned above, than any type of concrete piling heretofore proposed.

The present pile structure may be described briefly as one in which the concrete body of the pile is protected by a layerV of slabs made of material that is fully resistant to attack and disintegration, with joints between the slabs of an equally resistant character, so that the slabs together form a continuous protective layer at the surface of the concrete. Preferably the slabs will be made of porous, asphalt impregnated concrete, and will be cast and impregnated at a central plant and shipped out to the jobs. By reason of their small size and light weight, however, the slabs may be handled and transported at comparatively low cost; and in a single shipment, sufficient slabs may be transported to protect a large number of piles.

Two different methods may be used in applying the slabs to the pile. In accordance with one method, the slabs are first arranged as a permanent form into which the body or concrete core of the pile is cast, the slabs having surface irregularities or key recesses into which the concrete ilows, so that when the concrete sets, the slabs will have in effect become integrated with the body of the pile. In applying the slabs by the second method, the body of the pile is first cast, and the pre-cast slabs ap- L plied and bonded to the body by grout poured into key recesses within both the slabs and the body. Both of these methods may be used in forming different parts of the same pile, or the entire pile structure may be cast in accordance with either one of the methods.

The advantages and desirable departures from past practice made possible by the invention, include many additional features which would rel quire considerable space to set out at length. It is believed that a full understanding of the objects and features mentioned above, as well as all the additional aspects and details of the invention, can most readily be given by proceeding directly to a description of certain typical and illustrative embodiments of the invention. For this purpose reference is had to the accompariying drawings, in which:

Fig. 1 is a perspective showing the arrangement of form slabs and braces used in casting the pile, some of the slabs being removed to show more clearly their shapes and relative positions;

Fig. 2 is a transverse sectional View showing the slabs and braces in the aspect of Fig. l, after the slab form has been lled with concrete;

Fig. 3 is a perspective showing the cast pile after removal from the studs;

Fig. 4 is a fragmentary section taken in the vertical plane of line 4-4 of Fig. 3;

Fig. 5 is a plan of one of the top slabs in Figs. 1 and 2, inverted to show the key recesses;

Fig. 6 is a section on line 6-6 of Fig. 5;

Fig. '7 is a view, partly in section, showing the top portion of a driven pile supporting a floor n LLI structure and having subsequently applied protective slabs keyed to its upper extent;

Fig. 8 is an enlarged section on line 8-8 of Fig. 7;

Fig. 9 is a front elevational view showing the protective slabs applied to sheet piling;

Fig. l0 is a vertical section on line IIJ-III of Fig. 9;

Fig. 11 is a horizontal section on line I I-I I of Fig. 9;

Fig. 12 is an elevation showing a further variational form of the invention; and

Fig. 13 is an enlarged section on line I3-I3 of Fig. 12.

The form of the invention shown in Figs. 1 to 8 inclusive may best be explained by rst describing the method whereby a section of the pile is cast in a form composed of protective slabs, and then the procedure followed in applying slabs to the top portion of the pile after the latter has been driven. Reference is rst made to Figs. l and 2 for the purpose of describing the sequence of operations in building up the slab form and nally lling it with concrete in casting the intermediate section of the pile. First I lay a suitable platform Il on which is erected a series of brace structures II comprising uprights i2, cross pieces I3 and diagonal braces I4. A series of bottom slabs I5 are then laid end to end upon the platform Iii, and two courses of slabs it placed upon the bottom diagonal braces if! with their inner edges engaging slabs i5. I have shown the angularly placed slabs I6 each to have two elongated key recesses Ita with undercut sides and ends for the purpose of illustrating that if desired, not only the ends but the sides of the slab recesses may be undercut.

Fig. 5 illustrates the shape of the bottom slabs I5, as well as those in the top course hereinafter described, although the latter are provided with certain openings not present in the bottom slabs, as will later appear. It may be stated rst that all the slabs will be precast and formed of a suitable waterproof material or composition resistant to attack and disintegration by acids, alkalies, and other deteriorating agencies. Preferably the slabs are made of concrete impregnated with waterproofing material such as asphalt, the concrete having sufficient porosity to be thoroughly impregnated throughout the in terior of the slab. In this connection, reference is made to my copending application on Protective slabs for concrete, Ser. No. 667,251, led Apr. 2l, 1933, for a more complete description of the advantages and characteristics of slabs of this general type. It will suiice to observe here that the slabs may be made of any suitable waterproong material resistant to deterioration, though I find asphalt impregnated concrete to be particularly well suited for my purposes.

Each slab I5 is rectangular in shape, of substantially uniform thickness, and has one or more key recesses il, three here being shown as typical, having undercut or dove-tailed ends i8, and sides I9 which are beveled inwardly toward the base of the recesses. As will later appear, these recesses serve to iorm keys which securely bond the slab to the concrete body of the pile. The recesses are entirely contained within the slab so that the joint edges beyond the recesses are of the full thickness of the slab. In impregnating the slabs, the latter are immersed for a time in a bath of het asphalt and then removed when the asphalt has fully permeated the pores. The impregnated slabs are stood on end to cool and dry, and in order to insure complete drainage of asphalt from the key recesses I cast drain notches Ila within the undercut ends it of the recesses.

As shown in Fig. 2, the adjoining edges of slabs I5 and it are beveled to provide upwardly opening wedgeshaped joint spaces 20. Similarly shaped joint spaces are formed at the ends oi the slabs, corresponding to the later described joints illustrated in Fig. 4. As soon as slabs I and I6 are laid, joint spaces 28 and the similar joint spaces between the ends of the slabs are lled with hot asphalt which, by reason of its high temperature, has a tendency to melt the impregnating asphalt in the pores oi the concrete at the edges of the slab. The result is that the joint lling asphalt, when cooled and hardened, will have become substantially integrated with the asphalt with which the slabs are impregnated. There is thus formed a joint that is thoroughly water tight and resistant to frost, acids, alkalies and other such deteriorating agencies. For further details concerninf-T this type oi joint, see Patent No. 1,953,920, granted to me April 10, 1934, on Protected concrete structures.

After laying the three lowermost courses of slabs, I then place the side slabs 22 which are shaped similar 'to the bottom slabs I5, except that they have peripheral tongues extending along one side and end, and grooves within the remaining side and end. Tongue and groove joints 23 are formed between slabs it and 22, the top angularly extending edges of the former having grooves 2t which receive tongues 25 on the lower edges of slabs 2li'. The joints at 23 are sealed with asphalt by iirst filling grooves 24 with hot asphalt andthen placing slabs 22.- It may be mentioned that the joints between abutting ends of successive side slabs 22 will also be of the tongue and groove type, and will be lled with hot asphalt after the slabs have been placed, by pouring the joints from the top.

Before slabs 2S are positioned, the reenforcing steel is put into place. Slabs 26 are next put in place and held in the positions illustrated by temporary spreaders, not shown, placed between the upper ends of thc slabs to keep them in place while the concrete is being poured. Asphalt filled tongue and groove joints 2l, similar to thc pre viously described joints 23, connect slabs 22 and 2i? along 'their adjacent horizontally extending edges. The end joints between successive slabs 26 will however be similar to the later mentioned joints at see Fig. 4, in order that they may be poured from above.

All except the top slabs 29 having been placed and the joints cooled, concrete 39 is now poured into the interior space enclosed by the slabs and around suitable previously placed reenforcement 3i. Preferably the concrete will be tamped, vi-

brated or otherwise compacted into the slab form These top slabs 29 will be tamped rmly in place to compact the concrete beneath, and then, in order to insure that the joint recesses Il within the slabs will be entirely filled with concrete, grout is poured or forced under a slight pressure into the key recesses through holes 33 cast within the slabs. Air and surplus grout are at the same time displaced through another set of holes 34, there being, as illustrated in Fig. 5, inlet and outlet holes extending through the slab into each key recess. The adjacent edges of slabs 26 and 29 are beveled to form wedge-shaped joint spaces at 35, and the abutting ends of successive slabs 29 are beveled to form similar joint spaces as indicated at 28 in Fig. 4. After the top slabs have become bedded with their key recesses cornl pletely filled with grout, holes 33, 34 and joint spaces 28 and 35 are cleaned out, allowed to dry, and then filledV with hot asphalt. After the concrete has set for a period, the brace structures l I are removed.

At the same time the intermediate portion of the pile is being cast within permanent slabs as described, end portions of the pile extending beyond the slabs are also cast. As shown in Fig. 3, the driven end 31 of the pile is a solid concrete continuation of the concrete core 30 enclosed within the slabs, and has a cross sectional configuration conforming to the polygonal outer surface shape of the slab assembly. As shown in Fig. 4, the end slabs adjacent the driven end of the pile bear against shoulders 38 and form with the end 31, continuous smooth surfaces. If desired, asphalt filled joints may be formed at 38a between the end slabs and the driven end section of the pile.

In casting the opposite solid concrete end 39 of the pile, longitudinally extending key recesses 48 having undercut sides 4I, see Fig. 8, are formed in the surfaces of the concrete, the lower ends of the recesses being closed by inwardly beveled shoulders 42, see Fig. 3. Recesses 4B may be cast by pouring the concrete around correspondingly shaped form boards which may be withdrawn endwise from the recesses after the concrete has set sufficiently to 'hold its shape. I have not undertaken to illustrate forms to be used in casting the two end portions 31 and 39 of the pile, since the building of forms to cast these portions of the pile in the shapes illustrated requires no special skill.

After the concrete has set and hardened, the pile is ready for driving in an upright position with end section 39 at the top. By reason of the fact that initially the protective slabs are not applied to the uppermost section 39 of the pile, the pile driver blows are not transmitted directly to the slabs, but alone to the concrete core. Although as the pile is being driven, shearing stresses between the concrete core and the permanent form slabs may be set up due to the inertia of the slabs, any cleavage whatsoever at the joints formed by the slab key recessesr is prevented by the transverse shoulders, for example undercut shoulders I8 in Fig. 6, bearing against the concrete filling the recesses. In effect, the permanent slab form has become integrated with the body of the pile, and has substantially the same strength.

The piles ordinarily will be driven to a depth such that the intermediate section to which the slabs are applied will extend above and below the limits of rise and fall of the water level. EX- Vperience has shown that where the piles are driven in sea water beds, it is within these limits that the pile is subjected to greatest deterioration by reason of the alternate submergence and exposure to air. It is readily Aapparent that by reason of the integrated protective slab structure and the waterproof joints between the slabs,

the concrete body of the pile is rendered entirely immune to attack.

Since the'final depth to which a pile will be driven cannot bedefinitely ascertained in advance due to unknown conditions inthe soil and formation into which the pile is driven, it is necessary to adjust the height of the driven pile to suit the level of the structure which it is to support, either by cutting off or adding to its upper end. The present pile structure lends itself particularly to height adjustment after driving, and to final application of slabs in order that the pile may be protected throughout its entire extent above the water level. When the pile is driven, slabs 43 and 44, see Fig. 8, are placed around the top section 39, these slabs having self-contained undercut key recesses 45 and 46 similar to the key recesses ld in the previously described permanent form slabs I6. As illustrated, the slab lrecesses come directly opposite the undercut key recesses 40 cast in the body of the pile, s o that concrete poured into the recess forms a double key bonding the slabs to the body. The slabs have tongue and groove joints 41 along their vertically extending edges, and if desired, similar joints may be formed between these slabs and the upper end of the intermediate slab section, and between vertically successive slabs applied to the top section 40 of the pile.

In applying slabs 43 and 44, all the joints 41 may be iilled by pouring hot asphalt into the joint spaces from their' upper ends after the slabs have been arranged about the pile as shown in Fig. 8, or the sleeve formed by the slabs may first be made in sections by joining two or more of the slabs before applying them to the pile. After the joints have hardened, grout is poured into the upper ends of the body key recesses 40 and caused to flow down into and fully occupy the slab key recesses. grout forms keys 48 which securely bond the slabs to the concrete body of the pile. v

In cases where it is necessary to extend the pile above the upper end of section 39, slabs 43 and 44 may be built up to the desired height as a sleeve form, within which additional reenforcement steel may be placed and concrete poured. In this case complete sleeve sections may be formed of the slabs before being placed on the pile, and these sections placed one upon the other, with sealed joints between, until the desired height has been reached.

In Fig. 7 I show a protected floor structure supported on the upper end of the pile after the height of the latter has been adjusted as previously explained. A concrete beam form comprising a series of side slabs 50 and bottom slabs is built on a row of piles with the bottom slabs 5l resting upon their upper ends. These beam form slabs are similar in all respects to the previously described slabs applied to the pile, both as to waterproof characteristics and shape. The pile reenforcement 52 may be extended up into the beam form, and asphalt filled tongue and groove joints provided at 53 between the bottom slabs 5| and the lower edges of side slab 50. Additional slabs 54 may be suitably supported and joined to slabs 50 by asphalt filled joints at 55, to form the bottom protective layer of a concrete floor. After the slabs have been arranged as described, concrete is poured into `space 58 to form a horizontally extending beam, the licor 51 being poured at the same time. In setting, the concrete becomes securely1 bonded to the slabs, which in turn form Upon hardening, the 2- an integral continuous protective layer about the beam and the entire underside of the floor.

In Figs. 9 and ll I show a variational form of the invention in which the slabs are applied to the surface of sheet piling composed of individual piles 58 driven edge to edge and forming a continuous wall. 'Ihe piles are precast with tongues 59 and grooves 60 which interi-lt when the piles are driven in place. The individual piles are also precast with the View to protecting the surface 6l of the wall most subject to disintegration, as for example because of exposure to sea water, by the application and bonding of protective slabs thereto. For this purpose the piles 58 are cast with vertically extending key recesses 62 having undercut sides and extending continuously within that portion of the pile extent that is to be protected.

The slabs 63 may be applied to the face 6| of the sheet piling wall in various manners. For example, the lowermost horizontal course 64 of the slabs may be supported in place, the end tongue and groove joints 65 filled with hot asphalt, and then the upper courses 66 and 61 i applied successively, the horizontal tongue and groove joints 68 and the vertical joints 65 being poured as the slab structure is built up to the level of the top 58a of the piling. After the several slab courses have been placed and the joints allowed to harden, grout is poured or forced down through key recesses 62 in the pile, completely filling these recesses and also the key recesses S9 in the slabs. After the grout sets, the slabs will have become bonded and keyed to the surface of the piling, forming a continuous waterproof protective layer. Ordinarly the slabs need be applied to only a sufficient vertical extent of the pile that the lower slab course will at all times be submerged beneath the level of the water to which the piling is exposed.

Instead of first building up the successive slab courses to the top of the piling and then pouring grout to fill the key recesses of all the slabs at once, if found necessary or for any reason desirable, the grout may be poured into the key recesses after each horizontal slab course is laid. Since in this case the grout will be poured at intervals to shallower depths, a better opportunity may be given to avoid forming air pockets within the recesses, since the air may more readily escape.

After the slabs have been applied to the face of the sheet piling wall as described, a waling may be cast on the top of the piling and protected by slab courses continuing upwardly from those previously applied to the piling. In casting the waling I first place one or more courses 'Ill of slabs on the previously laid courses, and connect the individual slabs with tongue and groove waterproof joints of the character previously described. These slab courses 'l0 serve as permanent forms against which the concrete for the waling 'H is poured, other temporary forms being erected to cast the waling in the shape indicated.

Where it is desired to cast an individual waling to be applied to a wall or sheet piling, this waling can be precast within protective slabs and then mounted. Thus in Fig. l0, I show a waling 19 placed at or below the low water level and attached to the piling by horizontal tie rods 8l). The waling is precast by pouring concrete into slabs 8|, 82, and 83, the top slabs 84 being applied last and the enclosed space nally filled by poiuing or forcing in grout through apertures in these top slabs, as previously described with reference to Fig. 5. A protective closure 85 through which the tie rod is to extend, may be formed of small-size slabs or of a single impregnated concrete tube, and placed in the position shown before the concrete 85 is poured. Waterproof tongue and groove joints are formed between the slabs encasing the waling, as shown, and also at 8l between the lowerrnost slab 64 and the top slab 84 of the waling.

Figs. l2 and 13 show a variational form of the invention in which an individual pile is entirely enclosed within a protective sleeve made up of slabs applied to the pile in essentially thev same method as that just described with reference to the sheet piling. In Fig. 13 I show a precast square concrete pile 12 having longitudinally extending undercut key recesses '13 formed in each of its four surfaces. Protective slabs 'i4 applied to the faces of the pile have end key recesses "E5 directly opposite the pile key ways I3, and have asphalt filled tongue and groove joints at 1S and 'i1 along their engaging vertically and horizontally extending edges. The lowermost slabs 'lila are supported on a shoulder 'la which may be cast integrally with or otherwise fastened to the pile. As in the forms of the invention shown in Figs. 8 and 1l, the slabs 'M are bonded to the sur- Vface of the pile by grout poured into recesses 13.

In all the previously described forms of the invention in which the slabs have been applied to driven` piles, the latter have been precast with grout receiving recesses in their surfaces. I may state that it is readily possible and fully practical to apply the slabs to driven piles that have not been specifically cast to provide bonding irregularities, simply by forming such irregularities in the pile surface by the use of air drills or other suitable implements. The irregularities or grout receiving spaces so formed need not necessarily take the shape of undercut key ways such as I have shown in the cast piles, but they may be of any character or configuration that will enable a secure bond to be had between the slabs and the pile. As an alternative method of applying the slabs to piles that have not had bonding recesses formed in their surfaces, or to smooth surface piles, I may apply coarse wire mesh, reenforcernent materials or the like, to the pile, then place the slabs against the wire mesh or reenforcernent, and nally pour grout into the space between the slabs and the pile. In this case the reenforcement acts to bond the grout to the pile, instead of irregularities formed in the surface of the latter. v

The herein described methods of initially casting the pile, andV for applying slabs to and extending the driven pile, are specifically dealt with in my copending applications on Method for making protected piling, Ser. No. 32,513, filed July 22, 1935, and Method of forming and extending driven piling, Ser. No. 32,512, filed on the same date.

I claim:

l. A protected pile structure of the character described comprising a solid concrete body having longitudinally extending recesses with undercut sides formed in its surface, and a plurality of preformed slabs applied to said body and having recesses with undercut sides formed in their inner faces adjacent the body surface and directly opposite the first mentioned recesses, said slabs being bonded to the body by grout within said body and slab recesses.

2. A protected pile structure of the character fili described comprising, a body, a plurality of preformed slabs applied to the surface of said body, each of said slabs having a key recess extending longitudinally of the pile, and a transverse shoulder closing one end ofthe recess, said slab recess and also a key recess formed in the surface of said body containing concrete bonding the slab to the body of the pile and said shoulder taking the load imposed on the slab while the pile is being' driven.

3. A protected pile structure of the character described comprising, a body, a plurality of preformed slabs applied to the surface of said body, each of said slabs having a key recess extending longitudinally of the pile, and a transverse undercut shoulder closing the upper end of the recess, said slab recess and also a key recess formed in the surface of said body containing concrete bonding the slab to the body of the pile and said shoulder taking the load imposed on the slab while the pile is being driven.

4. A protected pile structure of the character described comprising, a vertically extending concrete body, a plurality of preformed protective slabs bonded to the surface of the body starting at a point spaced a substantial distance below its upper end, the upper portion of the body above said slabs having formed in its surface longitudinally extending recesses adapted to receive grout for bonding subsequently applied slabs thereto.

5. A protected pile structure of the character described comprising, a vertically extending concrete body, a plurality of preformed protective slabs bonded to the surface of the, body starting at a point spaced a substantial distance below its upper end, the upper portion of the body having key recesses formed in its surface, and a plurality of protective slabs applied to said upper 40 portion of the body and having key recesses in their inner surfaces directly opposite said body recesses, the last mentioned slabs being bonded to the body by grout within the slab and body recesses.

6. A protective pile structure of the character described comprising, a vertically extending concrete body, a plurality of preformed protective slabs bonded to the surface of a lower portion of the body starting at a point spaced a substantial distance below its upper end, and means providing irregularities on the surface of the body above said slabs for bonding additional slabs to the body after the pile is driven.

7. A protected pile structure of the character described comprising, a vertically extending concrete body of polygonal cross section having a plurality of plane surfaces, a plurality of preformed protective slabs bonded to the surface of a lower portion of said body, the upper portion of said body above said slabs having formed in each of its surfaces an elongated recess extending longitudinally of the pile and adapted to receive grout for bonding subsequently applied slabs to the body.

8. A protected pile structure of the character described comprising, a solid concrete body having a bottom driven end, a plurality of preformed slabs bonded to the surface of said body starting at a point above said driven end and forming a continuous protective layer terminating below the upper end of the body, the cross sectional distance between opposite surfaces of said body below the slabs being greater than the distance between corresponding surfaces towhich said slabs are applied, and the upper surface of the body above said slabs having longitudinally extending recesses formed therein to receive grout for bonding subsequently applied slabs thereto.

JOHN W. B. BLACKMAN. 

